Limpador de filamento para Metamaquina2. Filament wiper for the Metamaquina2. Works for some Printrbots too. Just cut some sponge or fabric and place is inside the box. No elastic necessary. It should clip on snuggly. Some sanding down on the clip on bars might be needed to smooth them out and make it slide into place easier. I use the elastic just to prevent the latch from opening (has happened before).